WHATELY — For the third time, South County’s new regional ambulance service is exploring the possibility of purchasing the Western Massachusetts Regional Library System’s building in Whately to use as its permanent base of operations.

At its meeting last Tuesday night, the South County EMS Board of Oversight poured over a map of the building’s layout designed by William Swasey, South Deerfield Fire Chief and board member, and tossed around ideas about what amenities the service would need to have in the building, as well as how to make it all fit.

The building is expected to be shared with the South County Senior Center and Frontier Community Access Television.

Board member and Deerfield Selectman David Wolfram said the building’s current occupant, the Western Massachusetts Regional Library System, would rent space from the new owner for up to five years.

The three towns that are served by South County EMS — Deerfield, Whately and Sunderland — first expressed interest in the building, located in Whately’s industrial park, in the summer of 2013. In December of that year, the towns said they weren’t ready to make an offer and the library system reached an agreement with another buyer.

In February 2014, that deal fell through due to the prospective buyer’s inability to sell their current building, and the library renewed talks with the towns and ambulance service.

Then, for a second time, the library decided to sell the building to a private business. According to Gregory Pronevitz, the director of the Massachusetts Library System, which oversees the Western Massachusetts Regional Library System, that deal has now fallen through as well.

Pronevitz said the library would be more than willing to work with the three towns to develop a multi-use facility.

“We’ve had interest from the towns in the past, but they’ve always brought an undefined offer while other offers were on the table,” Pronevitz said. “We’re looking for a reasonable proposal on a reasonable timeline that would solve this issue for us.”

Pronevitz said the building would be an ideal location for the ambulance service, as it is located at the point where the three towns meet.

He said the Western Massachusetts Regional Library System would maintain a presence in the region.

The Board of Oversight will meet jointly with the boards of selectmen of each of the three towns and FCAT representatives Thursday at 6 p.m. in Whately’s Center School Offices to discuss the matter. The meeting is likely to be conducted in executive session, according to Whately’s website calendar.

The old Sunderland firehouse on North Main Street has also been considered as a possible home for the ambulance service.

For now, the service’s main ambulance is stationed at the South Deerfield Fire Department, while its other two ambulances are housed in Whately and Sunderland. It must find a new location within the next three years.